Thermistor with plastic package structure

Abstract

The utility model discloses a thermistor with a plastic packaging structure, which comprises a shell, a thermistor chip and a flexible heat conduction piece, a packaging inner cavity is arranged in the shell, the flexible heat conduction piece and the thermistor chip are respectively assembled in the packaging inner cavity, the flexible heat conduction piece comprises a heat conduction base plate and a heat conduction lug which are arranged in a molding manner, and the heat conduction base plate is arranged in the packaging inner cavity. The bottom surface of the heat conduction chassis is connected to the top surface of the thermistor chip in an abutting manner, and the heat conduction lug protrudes out of the top opening of the packaging inner cavity; a plastic package part is arranged above the heat conduction base plate, and a limiting ring is formed on the side wall of the plastic package part; a limiting groove is formed in the upper middle portion of the inner wall of the assembling inner cavity, and the limiting ring and the limiting groove are clamped, embedded and matched in a limiting mode. Compared with the prior art, the stability of the packaging structure is improved, and the service life of the thermistor is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of thermistors, in particular to a thermistor with a plastic-sealed structure. Background Art

[0002] A thermistor primarily consists of a thermal probe, leads, and a housing. Thermistors are typically two-terminal devices, but some are three-terminal or four-terminal. Their structure generally includes a housing, a thermistor chip mounted within a cavity enclosed by the housing, and two leads electrically connected to the thermistor chip and extending outside the housing. A cavity is provided on a side wall of the housing corresponding to the thermistor chip, communicating with the cavity. A flexible thermal conductor is also fixedly mounted at the cavity to conduct heat between the thermistor chip and the object being measured. The flexible thermal conductor serves as a heat transfer medium between the thermistor chip and the object being measured. However, the housing-end packaging structure of some current thermistors suffers from poor stability and is prone to falling off, causing the flexible thermal conductor to loosen and fail to effectively conduct heat. Utility Model Content

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a thermistor with a plastic package structure, thereby improving the stability of the package structure and prolonging the service life of the thermistor.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a thermistor with a plastic-sealed structure, comprising a shell, a thermistor chip and a flexible thermally conductive member, a packaging cavity is provided inside the shell, the flexible thermally conductive member and the thermistor chip are respectively assembled in the packaging cavity, the flexible thermally conductive member comprises a molded thermally conductive chassis and a thermally conductive lug, the bottom surface of the thermally conductive chassis is abutted against the top surface of the thermistor chip, and the thermally conductive lug protrudes from the top opening of the packaging cavity; a plastic-sealed member is provided above the thermally conductive chassis, and a limit ring is formed on the side wall of the plastic-sealed member; a limit groove is formed in the middle and upper part of the inner wall of the assembly cavity, and the limit ring is engaged with the limit groove for limited positioning.

[0005] In a further technical solution, the plastic package is made of epoxy resin, a through hole is formed in the middle of the plastic package, and the thermal conductive lug is passed through the through hole and protrudes from the plastic package.

[0006] In a further technical solution, the bottom surface of the package cavity is provided with supporting feet, which cooperate with the bottom surface of the thermistor chip for support.

[0007] In a further technical solution, at least two pinholes are provided on the bottom surface of the package cavity; more than two pins are provided on the bottom of the thermistor chip, and each pin is inserted into a corresponding pinhole and extends out of the shell.

[0008] In a further technical solution, a bottom cover is provided at the bottom of the shell, and a cover eave is formed on the edge of the bottom cover. The bottom cover is provided at the bottom of the shell, and the inner wall of the cover eave is fastened to the shell; the supporting feet and the needle hole are respectively provided on the bottom cover.

[0009] In a further technical solution, an adhesive structure is provided between the cover eaves and the shell.

[0010] In a further technical solution, a waterproof structure is provided between the needle hole and the pin, and the waterproof structure is formed by curing polyurethane resin.

[0011] In a further technical solution, the outer wall of the shell is provided with a thermochromic coating.

[0012] In a further technical solution, the top surface of the plastic package is provided with an anti-oxidation structure, and the anti-oxidation structure is formed by curing an antioxidant.

[0013] After adopting the above structure, the advantages of the present invention over the prior art are as follows: the present invention provides a thermistor with a plastic sealing structure, by providing a limiting slot structure in the heat sealing structure of the thermistor, the molded plastic sealing part is locked and limitedly cooperated with the limiting groove, thereby preventing the plastic sealing part from falling off, improving the stability of the packaging structure, preventing the flexible heat conductive part from loosening, ensuring the stable operation of the heat transfer structure of the thermistor, and extending the service life of the thermistor; through the separate shell structure, the difficulty of assembling the thermistor is reduced, the overall structural strength and reliability are guaranteed, the internal thermistor chip can be disassembled and replaced, and the thermistor is repairable; the top of the plastic sealing part is provided with an anti-oxidation structure, which makes the packaging structure of the thermistor more stable and further extends its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 It is a structural diagram of the utility model;

[0016] Figure 2 It is a cross-sectional schematic diagram of the present utility model;

[0017] Figure 3 It is an exploded schematic diagram of the present utility model. DETAILED DESCRIPTION

[0018] The following are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention.

[0019] like Figures 1 to 3As shown, the present invention provides a thermistor with a plastic-sealed structure, comprising a housing 1, a thermistor chip 3, and a flexible thermally conductive member 4. A packaging cavity is provided inside the housing 1, and the flexible thermally conductive member 4 and the thermistor chip 3 are respectively assembled in the packaging cavity. The flexible thermally conductive member 4 includes a molded thermally conductive chassis 41 and a thermally conductive lug 42. The bottom surface of the thermally conductive chassis 41 is abutted against the top surface of the thermistor chip 3, and the thermally conductive lug 42 protrudes from the top opening of the packaging cavity; a plastic sealing member 5 is provided above the thermally conductive chassis 41, and a limit ring 51 is formed on the side wall of the plastic sealing member 5; a limit groove 11 is formed in the middle and upper part of the inner wall of the assembly cavity, and the limit ring 51 is engaged with the limit groove 11 for limiting position.

[0020] In this embodiment, the housing 1 is cylindrical and has two openings. A bottom cover 2 is provided at its base. The edge of the bottom cover 2 is formed with a canopy. The bottom cover 2 is positioned over the bottom of the housing 1, and the inner wall of the canopy is securely fastened to the housing 1. Legs 22 and needle holes 21 are provided on the bottom cover 2. An adhesive structure is provided between the canopy and the housing 1. This detachable housing structure reduces the difficulty of thermistor assembly, ensures overall structural strength and reliability, and allows for easy disassembly and replacement of the internal thermistor chip 3, making the thermistor repairable.

[0021] The core technology of the present utility model is that, by arranging a limiting groove 11 in the inner cavity of the package, the flowing epoxy resin material can fill the limiting groove 11 during the packaging period, so that the side wall of the cured plastic package 5 can form a limiting ring 51. The limiting ring 51 is engaged and limited with the limiting groove 11 to prevent the plastic package 5 from loosening and exiting the inner cavity of the package, resulting in the disconnection of the heat conduction contact between the flexible thermal conductive part 4 and the thermistor chip 3, thereby damaging the thermistor and preventing it from working normally.

[0022] A preferred embodiment is to provide an anti-oxidation structure on the top surface of the plastic package 5, which is formed by curing an antioxidant. The anti-oxidation structure on the top of the plastic package makes the thermistor packaging structure more stable, prevents the plastic package 5 from shrinking, and further extends its life.

[0023] Specifically, a through hole 52 is formed in the middle of the plastic package 5 , and the thermal conductive lug 42 is passed through the through hole 52 and protrudes from the plastic package 5 .

[0024] Specifically, the bottom surface of the package cavity is provided with a support foot 22 , and the support foot 22 is supported and matched with the bottom surface of the thermistor chip 3 .

[0025] Specifically, at least two pinholes 21 are formed on the bottom surface of the package cavity; more than two pins 31 are formed on the bottom of the thermistor chip 3 , and each pin 31 is inserted into a corresponding pinhole 21 and extends out of the housing 1 .

[0026] Specifically, a waterproof structure is provided between the needle hole 21 and the pin 31 , and the waterproof structure is formed by curing polyurethane resin.

[0027] Specifically, the outer wall of the housing 1 is provided with a thermochromic coating.

[0028] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, according to the concept of the present invention, there may be changes in the specific implementation methods and application scope. The content of this specification should not be understood as limiting the present invention.

Claims

1. A thermistor with a plastic encapsulation structure, characterized in that: The invention comprises a housing (1), a thermistor chip (3) and a flexible heat-conducting member (4); a packaging inner cavity is provided inside the housing (1); the flexible heat-conducting member (4) and the thermistor chip (3) are respectively mounted in the packaging inner cavity; The flexible heat-conducting component (4) comprises a heat-conducting chassis (41) and a heat-conducting lug (42) which are molded and arranged, wherein the bottom surface of the heat-conducting chassis (41) is abutted against the top surface of the thermistor chip (3), and the heat-conducting lug (42) protrudes from the top opening of the package inner cavity; a plastic sealing component (5) is arranged above the heat-conducting chassis (41), and a limiting ring (51) is molded on the side wall of the plastic sealing component (5); a limiting groove (11) is molded in the middle and upper part of the inner wall of the assembly inner cavity, and the limiting ring (51) is engaged and limitedly matched with the limiting groove (11).

2. The thermistor with a plastic-encapsulated structure according to claim 1, characterized in that: The plastic sealing member (5) is formed by epoxy resin molding, a through hole (52) is molded in the middle of the plastic sealing member (5), and the heat conductive lug (42) is inserted through the through hole (52) and protrudes from the plastic sealing member (5).

3. The thermistor with a plastic-encapsulated structure according to claim 2, characterized in that: The bottom surface of the packaging inner cavity is provided with a support foot (22), and the support foot (22) is supported and matched with the bottom surface of the thermistor chip (3).

4. The thermistor with a plastic-encapsulated structure according to claim 3, characterized in that: The bottom surface of the package inner cavity is also provided with at least two pinholes (21); the bottom of the thermistor chip (3) is provided with more than two pins (31), each pin (31) is respectively inserted into a corresponding pinhole (21) and extends out of the housing (1).

5. The thermistor with a plastic-encapsulated structure according to claim 4, characterized in that: The bottom of the shell (1) is provided with a bottom cover (2), the edge of the bottom cover (2) is formed with a cover eave, the bottom cover (2) is covered on the bottom of the shell (1), and the inner wall of the cover eave is tightly matched with the shell (1); the supporting foot (22) and the needle hole (21) are respectively provided on the bottom cover (2).

6. The thermistor with a plastic-encapsulated structure according to claim 5, characterized in that: An adhesive structure is provided between the cover eaves and the shell (1).

7. The thermistor with a plastic-encapsulated structure according to claim 6, characterized in that: A waterproof structure is provided between the needle hole (21) and the pin (31), and the waterproof structure is formed by curing polyurethane resin.

8. The thermistor with a plastic-encapsulated structure according to claim 1, characterized in that: The outer wall of the housing (1) is provided with a thermochromic coating.

9. The thermistor with a plastic-sealed structure according to claim 1, characterized in that: The top surface of the plastic sealing part (5) is provided with an anti-oxidation structure, and the anti-oxidation structure is formed by curing an antioxidant.

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